JComboBox fires ActionEvent when using Arrow Keys on the JComboBox popupwindow

Question

Hi,
Situation:
I have a JComboBox and an ActionListener (ItemStateListener is
the same) attached to the JComboBox component.
I have several items in the ComboBox.
At runtime I open the ComboBox with arrow Key (DOWN Key)
(popupwindow is visible) and go through the items with the arrow
keys (UP or DOWN).
Every time I change from one item to another with the arrow
keys , the ActionListener is called, although the popupwindow is
still open (ENTER was not pressed). I think this is very bad,
because I do not have chance to divide between "the user is
travelling around in the combo looking for the right item"
and "the user selects the item he wants".
When you walk through the items with the mouse, the
ActionListener is not called.
Question:
Is there any chance to prevent the ComboBox fireing
ActionEvents, when the users walks through the items with Arrow
Keys?
I've looked at the L&F Classes, but in my opinion it is not the
right way to overwrite the ComboUI classes.
Any ideas?
Loeri

Answer 1

Try using the PopupMenuListener.
     m_objListNameComboBox.addPopupMenuListener(/* your listener */);
Do what you want in the method popupMenuWillBecomeInvisible.
I use it to get the LAST selected item in the combobox.
     // Implementation of PopupMenuListener
     public void popupMenuWillBecomeVisible(PopupMenuEvent e)
          m_intSelectedIndex = m_objListNameComboBox.getSelectedIndex();
     // Implementation of PopupMenuListener
     public void popupMenuWillBecomeInvisible(PopupMenuEvent e)
          if (m_intSelectedIndex != m_objListNameComboBox.getSelectedIndex())
               // do what you want!